Dental instruments



April 5, 1955 P. J. TASCHER 2,705,368

DENTAL INSTRUMENTS Filed April 29, 1954 INVENTOR: PAUL J. TAEGHER United States Patent DENTAL INSTRUMENTS Paul J. Tascher, Glen Cove, N. Y.

Application April 29, 1954, Serial No. 426,351

9 Claims. (Cl. 32-40) My invention relates to tools for pressing excessive mercury out of amalgam as it is necessary in dentistry, for example, when teeth are filled according to the following advantageous method:

Powdered silver or other suitable metal is mixed with considerably more mercury than adapted for properly hard crystallization of the amalgam preparation whereby this mixture is sufiiciently liquid for an initial filling of the small corners of the tooth cavity. Then, the excessive mercury is squeezed out of the remaining quantity of the mixture, preferably stepwise, and less soft portions of amalgam are used for the further filling. The entire filling must be finished within short time in order to make the several portions bind with each other in fresh and plastic condition before their crystallization and hardening and so that the drier portions suck some mercury from the softer portions whereby a substantially uniform amalgam filling of proper hardness throughout results.

Hitherto, tools for squeezing amalgam used to press the excessive mercury into the open. This has the disadvantages that mercury vapor mixes with the room air, endangers the health of persons staying in this room for considerable time, and constitutes a not recoverable waste of valuable mercury. Objects of my invention are to avoid these disadvantages, to keep the mercury pressed out of the amalgam within the tool, to collect mercury pressed out by several squeezes in an inner space of the tool, thereby to make unnecessary to carry out the squeeze over a tray and to avoid interruption of the dental operation by removal of the mercury whereby a quick filling of the tooth and a thorough binding of the portions of amalgam forming the filling is facilitated, and to release the collected mercury into a suitable receptacle at any later convenient time.

Other objects are to release the mercury through an arm of the squeezing tool whereby the release into the mouth of a bottle-like receptacle is facilitated, to pro vide, for this purpose, this arm with a channel extending lengthwise to the lower end of the arm, to provide an automatically closing closure for the exit aperture of this channel, and to provide means for opening this closure conveniently, preferably with a finger nail, without contacting the mercury conducting surfaces of the arm.

Further objects are to facilitate the insertion of the amalgam of a squeeze cloth containing the same in the tool in best adapted position between the compressing surfaces, to make possible the observation of the position of this cloth and of the squeezing effect, and thereby to facilitate a correct and eflicient operation of the tool.

Another disadvantage of the known tools is that their squeezing effect depends on the individual strength and size of the hand of the operator whereby, for example, female assistants of dentists are often unable to exert sufficient pressure. A tool that is fit and convenient for one person, is often inconvenient or unfit for another person.

Still other objects of my invention are to avoid the latter disadvantage, to provide a tool adaptable to the hand strength and size of different persons, to provide the tool with separately made handles, to afiix these handles in lengthwise adjustable positions whereby the leverage of the tool can be varied, or/and to affix the handles exchangeably whereby handles of different shape and length may be used optionally and may be selected according to the individual requirement for convenient and correctly strong operation, and thereby further to facillitate and expedite a correct and efiicient use of the too Still further objects are to provide means for spreading the tool arms automatically after each squeeze, thereby to make possible the operation of the tool with less skill and effort, and to operate these means with a minimum of frictional resistance.

Still other objects and advantages will appear from the following description of an exemplifying embodiment of my invention, from the appended claims and from the accompanying drawing in which:

Fig. lshows a vertical cross-section of an illustrative embodiment of my invention, taken along the line 11 in Fig. 3.

Fig. 2 shows a view of the same embodiment seen from the left side in Fig. 1.

Fig. 3 shows a top view of the same embodiment.

Fig. 4 exemplifies a handle which may be used instead of a. handle incorporated in the embodiment shown in Figs. 1 to 3.

The shown embodiment is made of non-amalgamable metal and comprises an arm 2 consisting of a top piece and a handle 3, and another arm 4 consisting of a top piece 4 and a handle 5. The top pieces of the arms 2 and 4 are hinged to each other like the arms of a nut cracker by a pin or axle 6 which has an axis perpendicular to the plane defined by the lengthwise extensions of the arms. In the position of use which is shown in the drawing, the hinged ends of the arms are at their top.

The top piece of the arm 2 has an :inner space 7 which is covered by a solid wall 8. A channel 9 extends along an arc of a circle about the axis of the pin 6 from that side of this arm which faces the other arm to an opening of the space 7 which is opposite to the wall 8. The space 7 has an extension which reaches downward farther than this channel opening and preferably leads to a channel 11 having a continuation 12 extending lengthwise through the handle 3.

The other arm 4 has an extension 13 which, in the shown position in which the tool is :ready for squeezing operation, reaches into the channel 9 almost as far as the 1nner opening of this channel. The extension 13 is curved similarly as this channel, can turn with the arm 4 about the pin 6 and has an end 14 which preferably fits this opening slidably.

The space 7 serves for the insertion of a quantity of amalgam to be squeezed between the wall 8 and the part 14. Though it is possible to insert the amalgam through the channel 9 after withdrawing the extension 13 temporarily from this channel, I prefer to provide a more convenient and better observable access for the insertion of the amalgam. This access forms a funnel-like aperture 15 extending from the top surface of the arm 2 to the space 7.

The channel 12 terminates in an outlet aperture near the lower end of the handle 3. This aperture is closed by a suitable closure, for example, by a cover 16 which has an extension 17 forming a spring urging the cover into closing position. The spring 17 has an end aflixed to the handle 3, for example, by a screw 18. A projection 19 of the cover 16 is shaped so that a recess between this projection and the main part of the cover is formed for the insertion of a finger nail whereby the cover can be conveniently opened against the pressure of the spring 17.

The handles 3 and 5 are preferably made separately from and afiixed to their top pieces, for example, by screws 21. These handles are lengthwise adjustable or exchangeable with other handles or both adjustable and exchangeable. For example, the handles can be shifted in longitudinal bores of the respective top pieces while the screws 21 are temporarily loosened. Or other handles of different shape or length may be inserted in these bores instead of the handles 3 and 5. For example a handle 22 having a curvature snugly fitting the hand of the operator may replace the handle 5.

A spring 23 is positioned between the arm 2 and 4 and has one end affixed to one of these arms. For example, this spring end enters a groove 24 of the arm 4 and is afiixed to this arm by a screw 25. The other end of the spring 23 slides along the arm 2 when the arms are compressed. Preferably this other end carries a wheel or roller 26 whereby this sliding movement occurs with a minimum of friction.

The top piece of the arm 2 has two lateral pro ections 27 which may be shaped like cones with rounded points and which extend substantially parallel to the axis of the pin 6. These projections are higher or farther from the lower end of the tool than the center of gravity of the tool. Hence, when the tool is laid down on a table or on another horizontal surface while not use d, it will rest on the handle tips and on one of the pro ections 27 which are considerably higher than the handle tips whereby the channel 1112 will remain in a downwardly inclined position, and mercury received in this channel will remain confined in the tool.

The described tool may be operated as follows:

A quantity of amalgam containing an excess of mercury and sufficient for the intended tooth filling is wrapped in porous material. For example, this amalgam is surrounded by a folded piece of cloth 28 which is so twisted that the amalgam is confined in an about globular sack 29 formed by the lower end of the cloth. The amalgamcontaining end of the cloth 28 is introduced through the aperture into the space 7. The other end of the cloth may project over the top surface of the tool.

The tool is held about in the shown position with one hand spanning over both handles. By contracting this hand, the two arms are compressed against the relatively slight resistance of the spring 23. Thereby, the end 14 of the arm extension 13 is moved toward the wall 7 of the other arm and compresses the sack 29, pressing droplets of mercury through the pores of this sack. These droplets run down in the space 7 and eventually farther into the channel 12 and 11 where they remain during the filling of the tooth.

As soon as the hand pressure is relaxed, the spring 23 spaces the arms 2 and 4 as far as shown in Fig. 1. In this position, the tool is ready for repetition of the squeeze.

At any convenient time after one or several toothfillings, the mercury is released from the handle 3 into a suitable receptacle by opening the closure 16.

I desire it understood that my invention is not confined to the particular embodiment shown and descr bed, the same being merely illustrative, and that my invention may be carried out in other ways within the scope of the appended claims without departing from the spirit of my invention as it is obvious that the particular embodiment shown and described is only one of the many that may be employed to attain the objects of my invention.

Having described the nature of my invention, what I claim and desire to protect by Letters Patent is:

1. A tool for pressing excessive mercury out of amalgam, comprising two arms hinged to each other about an axis near their upper ends, one of said arms having an inner space for insertion of a quantity of amalgam and having a channel extending from the side facing the other arm to an opening of said space, said first mentioned arm having a solid wall bordering said space oppositeto said opening, said other arm having an extension reaching into said channel and movable about said axis toward said wall, said space extending between said wall and said opening and having a downward extension forming a channel terminating in an aperture near the lower end of said first mentioned arm, and a closure for said aperture.

2. A tool for pressing excessive mercury out of amalgam, comprising two arms hinged to each other about an axis near their upper ends, one of said arms having an inner space for insertion of a quantity of amalgam and having a channel extending from the side facing the other arm to an opening of said space, said first mentioned arm having a solid wall bordering said space opposite to said opening, said other arm having an extension reaching into said channel and movable about said axis toward said wall, said space extending between said wall and said opening and having a downward extension forming a channel terminating in an aperture near the lower end of said first mentioned arm, a closure for said aperture, and a spring urging said closure into closing position, said closure having a recess for the insertion of a finger nail.

3. A tool for pressing excessive mercury out of amalgam, comprising two arms hinged to each other about an axis near their upper ends, one of said arms having an inner space for insertion of a quantity of amalgam and having a channel extending from the side facing the other arm to an opening of said space, said first mentioned arm having a solid wall bordering said space opposite to said opening, said other arm having an extension reaching into said channel and movable about said axis toward said wall, said space extending from a top aperture of said first mentioned arm to a space part positioned between said wall and said opening and farther downward whereby mercury pressed out between said wall and said extension will flow to the bottom of said space.

4. A tool for pressing excessive mercury out of amalgam, comprising two arms hinged to each other about an axis near their upper ends, each of said arms comprising a hinged top piece and a separately made handle aflixed to said top piece, one of said arms having an inner space for insertion of a quantity of amalgam and having a channelextending from the side facing the other arm to an opening of said space, said first mentioned arm having a solid wall bordering said space opposite to said opening, said other arm having an extension reaching into said channel and movable about said axis toward said wall, said space extending between said wall and said opening and farther downward whereby mercury pressed out be tween said wall and said extension will flow to the bottom of said space.

5. A tool for pressing excessive mercury out of amalgam, comprising two arms hinged to each other about an axis near their upper ends, each of said arms comprising a hinged top piece and a separately made handle affixed to said top piece, one of said arms having an inner space for insertion of a quantity of amalgam and having a channel extending from the side facing the other arm to an opening of said space, said first mentioned arm having a solid wall bordering said space opposite to said opening, said other arm having an extension reaching into said channel and movable about said axis toward said wall, said space extending between said wall and said opening and having a downward extension forming a channel passing lengthwise through the handle of said first mentioned arm and terminating in an aperture near the lower end of said latter handle, and a closure for said aperture.

6. A tool for pressing excessive mercury out of amalgam, comprising two arms hinged to each other about an axis near their upper ends, each of said arms comprising a hinged top piece and a separately made handle exchangeably afiixed to said top piece, one of said arms having an inner space for insertion of a quantity of amalgam and having a channel extending from the side facing the other arm to an opening of said space, said first mentioned arm having a solid wall bordering said space opposite to said opening, said other arm having an extension reaching into said channel and movable about said axis toward said wall, said space extending between said wall and said opening and farther downward whereby mercury pressed out between said wall and said extension will flow to the bottom of said space.

7. A tool for pressing excessive mercury out of amalgam, comprising two arms hinged to each other about an axis near their upper ends, each of said arms comprising a hinged top piece and a separately made handle affixed to said top piece in lengthwise adjustable position whereby the length of said arms is variable, one of said arms having an inner space for insertion of a quantity of amalgam and having a channel extending from the side facing the other arm to an opening of said space, said first mentioned arm having a solid wall bordering said space opposite to said opening, said other arm having an extension reaching into said channel and movable about said axis toward said wall, said space extending between said wall and said opening and farther downward whereby mercury pressed out between said wall and said extension will flow to the bottom of said space.

8. A tool for pressing excessive mercury out of amalgam, comprising two arms hinged to each other about an axis near their upper ends, one of said arms having an inner space for insertion of a quantity of amalgam and having a channel extending from the side facing the other arm to an opening of said space, said first mentioned arm having a solid wall bordering said space opposite to said opening, said other arm having an extension reaching into said channel and movable about said axis toward said wall, said space extending between said wall and said opening and farther downward whereby mercury pressed out between Said wall and said extension will flow to the bottom of said space, and a spring positioned between said arms, having one end aflixed to one of said arms, having another end slidable along the other arm and urging said arms into a spaced position in which said arm extension is sufiiciently spaced from said wall for the interposition of a quantity of amalgam sufiicient for a dental operation.

9. A tool for pressing excessive mercury out of amalgam, comprising two arms hinged to each other about an axis near their upper ends, one of said arms having an inner space for insertion of a quantity of amalgam and having a channel extending from the side facing the other arm to an opening of said space, said first men- 15 tioned arm having a solid wall bordering said space opposite to said opening, said other arm having an extension reaching into said channel and movable about said axis toward said wall, said space extending between said wall and said opening and farther downward whereby mercury pressed out between said wall and said extension will flow to the bottom of said space, said first mentioned arm having lateral projections extending higher than the center of gravity of the tool substantially parallel to said axis whereby said latter arm will remain in a position rising toward its top when the tool is laid on a horizontal surface.

References Cited in the file of this patent UNITED STATES PATENTS 2,399,834 Seltzer May 7, 1946 

